Have you tried to change the option that says display new message indicator to "no" ? Otherwise, I think that you are going to have to deal with it. Sorry, but I haven't found a way to stop that, unless you have the device in a holster.
Every time a new email message is received, the backlight comes on. Is there a setting that will prevent this from happening?
I just sent myself an email (from my computer) and the backlight doesn't come on. I have new message indicator set to on so I'm not sure what's causing it. On income messages, I have it set to LED: on in my profile and under screen/keyboard, have Automatically Dim Backlight: On and LED Coverage Indicator: Off.